Internal-combustion engine



May 25, 1948. o. FRENCH 2,442,082

INTERNALTCOMBUSTION ENGINE Filed April 15, 1944 l8 W //J/ INVENTOR. $3,, 0.

Patented May 25, 1948 OFFICE INTERNAL-COMBUSTION ENGINE Louis 0. French, Milwaukee, Wis.

Application April 13, 1944, Serial No. 530,895

The invention relates to compression ignition two cycle internal combustion engines.

The opposed piston two cycle engine has demonstrated the advantages of end to end scavenging, and this engine with inclined inlet ports to produce a swirl of the entering air has also shown that turbulence improves the combustion process. The opposed piston engine, however, produces a thin pancake shape of combustion chamber that necessitates fiat sprays usually from two or more injectors and usually involves a duplication of heavy crank shafts and pistons at both ends of the engine, and this makes the engine expensive. The object of the present invention is to provide a two cycle compression ignition-internal combustion engine having end to end scavenging with means for insuring turbulence and good combustion of the fuel from a simple form of injector. More particularly, according to the present invention, I provide the cylinder with a belt of inlet ports uncovered by the piston and the head with a clerstory type of combustion chamber having a piston valve controlling a belt of exhaust ports, the scavenging of theicylinder preferably being done through a swirling stream of scavenge air, the combustion chamber being so associated with the main piston and the exhaust valve piston as to provide very efficient turbulence during the fuel injection period.

The invention further consists in the several features hereinafter set forth and more particularly defined by claims at the conclusion hereof.

In the drawings:

Fig. 1 is a vertical sectional view through an engine embodying the invention during the exhaust period;

Fig. 2 is a vertical sectional view taken on line 2-2 of Fig. 1;

I Fig. 3 is a detailed sectional view taken on the line 3-4 of Fig. 1:

Fig. 4 is a detailed sectional view of the combustion chamber duringfuel injection:

Fig. 5 is a detailed vertical sectional view taken on the line 5-5 of Fig. 4;

Fig. 6 is a view similar to Fi 4 showing certain modifications;

Fig. 7 is a view similar to Fig. 4 showing another modification;

Fig. 8 is a detailed sectional view taken on the line 8--8 of Fig. 7. r

Referring to the drawings, the numeral l0 the designates an engine cylinder having a belt of,

tangentially inclined scavenge .inlet ports II intermediate its ends, l2 a piston reciprocating in said cylinder and operatively connected bya con- 4 Claims. (01. 123-32) 2 necting rod l3 to the crankshaft M suitably journalled in the crankcase i5.

A cylinder head "3 is suitably secured to the upper end of the-cylinder l0 and has a combustion chamber l'l formed therein connected by a restricted throat passage 18 with said cylinder and by a restricted throat ill with a bore 20 at 1 right angles to said main cylinder and having a series of exhaust ports 2! formed therein intermediate its ends. The combustion chamber i1 is of generally toroidal shaped form.

A turbulator and exhaust control piston 22 reciprocates in the bore '20 and is driven from the crankshaft H by an eccentric 23 on said shaft, an eccentric connecting'rod 24 associated with said eccentric and connected to one arm 25 of a lever 26 including a shaft 21 pivotally supported on the engine frame, the other arm 28 of said lever being operatively connected to said piston 22 by a connecting rod 29 and wrist pin 30, the arm 28 having a separable end connection 3| with the shaft 21 to permit its release from said shaft, so that the piston 22 may be withdrawn from its bore, if desired, without disassembly of the other 25 parts of valve drive mechanism. The eccentric "a swirling body of scavenge air to thoroughly scour the cylinder of exhaust gases.

The piston l2 preferably has a projection 32 which fits rather closely the walls of the throat I ll except at one side as shown in Fig. 5, so that toward the end of the compression stroke the air within the main cylinder will pass at high velocity into the chamber l1 and through this squishing action between the piston and the head cause the air to swirl about the major axis D of said chamber as indicated by the arrows T in Fig. 5.- The area of the throats l8 and I9, respectively, is preferably not less than the combined area of the exhaust ports 2|.

The piston 22 has a conoidal shaped end adapted to fit rather closely the similarly inclined walls of the throat 19, so that near the end of its compression stroke an annular stream of air will be directed across the chamber I! and 2,44a,os2

3. impinge on the curved deflector surface 33 of the opposite side of the chamber, so that this air stream will be deflected outwardly about the minor axes D and across the major axis D of the torus as indicated by the arrows T' in Fig. 4.

A multi-jet fuel injector 34 of any suitable construction or-a pintle-type nozzle injector may be used to inject the liquid fuel charge along the major axis of the chamber I? and laterally thereof as indicated by the arrows F in Fig. 5. Injection of fuel preferably starts at about the time that the turbulence produced by the piston 22 has reached its peak, that is about fifteen to twelve degrees before the piston l2 reaches top or outer dead center position and ends about the time the turbulence produced by said piston l2 has reached its peak, that is when said piston l2 completes its outer stroke. Thus during the entire injection period the air in the combustion chamber is in a very turbulent condition due to swirl about its major axis D and the swirl across said axis and about each circular cross section of the toroidal chamber.

To further increase the swirl across the chamber [1 the end of the piston may have a hot tube cavity 35 formed or mounted therein with a restricted throat and the fuel injector 36 be disposed at right angles to the major axis 31 and constructed to deliver a pilot charge of fuel into said tube while main sprays 38 are directed outwardly and generally radially toward the periphery of said chamber I! as shown in Fig. 6. With this construction on combustion of the fuel charge in the cavity 35 this charge will be erupted from said cavity and impinge against the conical surface 38 of said nozzle or chamber and be deflected thereby around each minor axes section of the torus along with the'annular stream of gas that is forced into said chamber between the piston 22 and the throat l9.

Instead of having the major axis of the combustion chamber i1 alined with or parallel to that of the'axis of the cylinder in as shown, the axis of this chamber may be at right angles to the longitudinal axis of the cylinder and the end of the piston [2 be formed cone shaped similar to the end of the piston 22 and the end of the piston 22 be provided with a projection similar to the projection 32, these pistons cooperating with appropriately shaped throats similar to the passages l8 and i9, respectively, so that the main piston i2 would produce the cross swirl and the valve piston 22 the swirl about the major axis of the chamber, but the construction shown is preferred.

Figs. '1 and 8 show another form of combustion chamber for producing active turbulence during fuel injection. The combustion chamber 40 is of generally cylindrical form with a restrictedpassage or throat 4| between it and the cylinder and a restricted passage or throat 42 between it and the bore 20. The piston I2 is the same as the first described construction and functions similarly thereto to produce a swirl around the major axis of the chamber 40 during the injection period and the piston 22 is provided with a projection 43, similar to the projection 32 and arranged relative to the throat 52 so as to produce a swirl also around the major axis of the chamber 40 and in the same direction as that produced by the pistpn 12 as indicated by the arrows in Fig. '7. Thus the swirl about the chamber 40 is started by the piston 22 ahead of the dead center position of the piston l2 and is continued and augmented by the swirl produced by the piston I! while fuel is being injected into said chamber by the injector 44 which may be similar to the injector 34.

To permit ready machining of the chamber I! and also provide. a hot surface portion a part of its side may be in the form of a removable plug 45 and similarly the chamber 40 may be provided with a removable plug 46.

The scavenge air may be supplied to the chamber 41 surrounding the inlet ports either by a reciprocatory scavenge pump or by a suitable rotary pump or blower.

I desire it to be understood that this invention is not to be limited to any particular form or arrangement of parts except in so far as such limitations are included in the claims.

What I claim a my invention is:

1. In a two cycle compression ignition internal combustion engine, the combination of a pair of cylinders, one being of smaller diameter than the other, power pistons working in said cylinders,

the smaller of said pistons having a shorter stroke' than and a lead relative to the larger piston, the larger of said cylinders having tangentially disposed scavenge ports controlled by its piston and uncovered thereby near the end of its outer stroke, the smaller of said cylinders having exhaust ports controlled by its piston and uncovered thereby near the end of its outer stroke and in advance of the opening of said scavenge ports, a combustion chamber between said cylinders and in permanent retricted communication with the larger of said cylinders, the piston for the larger cylinder having a projection cooperating with said restricted communication near the end of its compression stroke to produce a swirl of gases in said combustion chamber across the axis of the swirl imparted by said tangential ports, and a fuel injector discharging into said combustion chamber during the time that the gases therein are subjected to the swirl imparted by the larger piston enterin said restricted communication.

2. In a compression ignition two cycle internal combustion engine, the combination of a pair of cylinders, one being of smaller diameter than the other, power pistons working in said cylinders, the smaller of said pistons having a shorter stroke than and a lead relative to the larger piston, the larger of said cylinders having tangentially disposed scavenge ports controlled by its piston and uncovered thereby near the end of its outer stroke, the smaller of said cylinders having exhaust ports controlled by its piston and uncovered thereby near the end of its'outer stroke and in advance of ing the time that the gases therein are in a state of maximum turbulence produced by the swirls induced by each of said pistons and said tangential scavenge ports.

8. In a compression ignition two cycle internal combustion engine, the combination of a pair of cylinders angularly disposed relative to each other and one of smaller diameter than the other, power pistons working in said cylinders, the smaller of 'said pistons having a shorter stroke than and a lead relative to the larger piston, the larger of said cylinders having scavenge ports controlled by its piston and uncovered thereby near the end of its outer stroke, the smaller of said cylinders having exhaust ports controlled by its piston and uncovered thereby near the end or its outer stroke and in advance or the opening 0! said scavenge ports, a toroidal combustion chamber between and in permanent restricted communication with both of said cylinders, each or said pistons having a part cooperating with said combustion chamber to induce a swirl of gases therein, one piston inducing a swirl about the major axis of said combustion chamber and the other about its minor axes, and a fuel iniector discharging fuel into said combustion chamber during the time that the gases therein are in a state or maximum turbulence produced by the swirls induced by each of said pistons.

4. In a compression ignition two cycle internal engine. the combination oi a pair of cylinders angularly disposed relative to each other and one of smaller diameter than the other, power pistons working in said cylinders, the smaller of said pistons having a shorter stroke than and a lead relative to the larger piston, the larger of said cylinders having scavenge ports controlled by its piston and uncovered thereby near the end or its outer stroke, the smaller of said cylinders having exhaust ports controlled by its piston and uncovered thereby near the end of its outer stroke and in advance of the opening of said scavenge ports,

- a toroidal shaped combustion chamber between and in permanent restricted communication with both of said cylinders. each of said pistons having a part cooperating with said combustion chamber to induce a swirl of gases therein, one piston inducing a swirl about the major axis of 6 said combustion chamber and the other about its minor axes, one of said pistons having a hot tube cavity therein, and a fuel injector arranged toinject a Jet 01 fuel into said cavity to further augment the swirl induced by this piston and to inject Jets of fuel radially of said combustion chamber during the time that the gases therein are in a state of maximum turbulence produced by the swirls induced by each of said pistons.

LOUIS O. FRENCH.

REFERENCES CITED The following references are oi' record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,425,946 Crossley et a1. Aug. 15, 1922 1,450,567 Tartrais Apr. 3, 1923 1,521,807 Ford Jan. 6, 1925 1,653,925 Petter et a]. Dec. 27, 1927 1,823,399 Hemmingsen Sept. 15, 1931 1,867,683 Sperry July 19, 1932 2,046,003 Scott June 30, 1936 2,048,223 Scott July 21, 1936 2,076,030 Kahllenberger Apr. 6, 1937 2,126,376 Curtis Aug. 9, 1938 2,148,854 Bokemuller Feb. 28, 1939 2,367,565 Curtis Jan. 16, 1945 FOREIGN PATENTS Number Country Date 397,840 Great Britain Aug. 25, 1933 852,718 France Mar. 1, 1940 

